math/test/hypot_test.cpp
2019-08-10 08:50:12 -04:00

131 lines
5.0 KiB
C++

// (C) Copyright John Maddock 2005.
// Use, modification and distribution are subject to the
// Boost Software License, Version 1.0. (See accompanying file
// LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
#include <pch_light.hpp>
#define BOOST_MATH_OVERFLOW_ERROR_POLICY ignore_error
#define BOOST_TEST_MAIN
#include <boost/test/unit_test.hpp>
#include <boost/test/tools/floating_point_comparison.hpp>
#include <boost/math/special_functions/math_fwd.hpp>
#include <cmath>
#ifdef BOOST_NO_STDC_NAMESPACE
namespace std{ using ::sqrt; }
#endif
//
// test_boundaries:
// This is an accuracy test, sets the two arguments to hypot to just
// above or just below various boundary conditions, and checks the accuracy
// of the result. The values computed at double precision will use a
// different computation method to those computed at float precision:
// as long as these compute the same values then everything's OK.
//
// Tolerance is 2*epsilon, expressed here as a persentage:
//
static const float tolerance = 200 * (std::numeric_limits<float>::epsilon)();
const float boundaries[] = {
0,
1,
2,
(std::numeric_limits<float>::max)()/2,
(std::numeric_limits<float>::min)(),
std::numeric_limits<float>::epsilon(),
std::sqrt((std::numeric_limits<float>::max)()) / 2,
std::sqrt((std::numeric_limits<float>::min)()),
std::sqrt((std::numeric_limits<float>::max)()) / 4,
std::sqrt((std::numeric_limits<float>::min)()) * 2,
};
void do_test_boundaries(float x, float y)
{
float expected = static_cast<float>((boost::math::hypot)(
#ifndef BOOST_MATH_NO_LONG_DOUBLE_MATH_FUNCTIONS
static_cast<long double>(x),
static_cast<long double>(y)));
#else
static_cast<double>(x),
static_cast<double>(y)));
#endif
float found = (boost::math::hypot)(x, y);
BOOST_CHECK_CLOSE(expected, found, tolerance);
}
void test_boundaries(float x, float y)
{
do_test_boundaries(x, y);
do_test_boundaries(-x, y);
do_test_boundaries(-x, -y);
do_test_boundaries(x, -y);
}
void test_boundaries(float x)
{
for(unsigned i = 0; i < sizeof(boundaries)/sizeof(float); ++i)
{
test_boundaries(x, boundaries[i]);
test_boundaries(x, boundaries[i] + std::numeric_limits<float>::epsilon()*boundaries[i]);
test_boundaries(x, boundaries[i] - std::numeric_limits<float>::epsilon()*boundaries[i]);
}
}
void test_boundaries()
{
for(unsigned i = 0; i < sizeof(boundaries)/sizeof(float); ++i)
{
test_boundaries(boundaries[i]);
test_boundaries(boundaries[i] + std::numeric_limits<float>::epsilon()*boundaries[i]);
test_boundaries(boundaries[i] - std::numeric_limits<float>::epsilon()*boundaries[i]);
}
}
void test_spots()
{
static const float zero = 0;
for(unsigned i = 0; i < sizeof(boundaries)/sizeof(float); ++i)
{
BOOST_CHECK_EQUAL(boost::math::hypot(boundaries[i], zero), std::fabs(boundaries[i]));
BOOST_CHECK_EQUAL(boost::math::hypot(-boundaries[i], zero), std::fabs(-boundaries[i]));
BOOST_CHECK_EQUAL(boost::math::hypot(boundaries[i], -zero), std::fabs(boundaries[i]));
BOOST_CHECK_EQUAL(boost::math::hypot(-boundaries[i], -zero), std::fabs(-boundaries[i]));
for(unsigned j = 0; j < sizeof(boundaries)/sizeof(float); ++j)
{
BOOST_CHECK_EQUAL(boost::math::hypot(boundaries[i], boundaries[j]), boost::math::hypot(boundaries[j], boundaries[i]));
BOOST_CHECK_EQUAL(boost::math::hypot(boundaries[i], boundaries[j]), boost::math::hypot(boundaries[i], -boundaries[j]));
BOOST_CHECK_EQUAL(boost::math::hypot(-boundaries[i], -boundaries[j]), boost::math::hypot(-boundaries[j], -boundaries[i]));
BOOST_CHECK_EQUAL(boost::math::hypot(-boundaries[i], -boundaries[j]), boost::math::hypot(-boundaries[i], boundaries[j]));
}
}
if((std::numeric_limits<float>::has_infinity) && (std::numeric_limits<float>::has_quiet_NaN))
{
static const float nan = std::numeric_limits<float>::quiet_NaN();
static const float inf = std::numeric_limits<float>::infinity();
BOOST_CHECK_EQUAL(boost::math::hypot(inf, nan), inf);
BOOST_CHECK_EQUAL(boost::math::hypot(-inf, nan), inf);
BOOST_CHECK_EQUAL(boost::math::hypot(nan, inf), inf);
BOOST_CHECK_EQUAL(boost::math::hypot(nan, -inf), inf);
for(unsigned j = 0; j < sizeof(boundaries)/sizeof(float); ++j)
{
BOOST_CHECK_EQUAL(boost::math::hypot(boundaries[j], inf), inf);
BOOST_CHECK_EQUAL(boost::math::hypot(-boundaries[j], inf), inf);
BOOST_CHECK_EQUAL(boost::math::hypot(inf, boundaries[j]), inf);
BOOST_CHECK_EQUAL(boost::math::hypot(inf, -boundaries[j]), inf);
BOOST_CHECK_EQUAL(boost::math::hypot(boundaries[j], -inf), inf);
BOOST_CHECK_EQUAL(boost::math::hypot(-boundaries[j], -inf), inf);
BOOST_CHECK_EQUAL(boost::math::hypot(-inf, boundaries[j]), inf);
BOOST_CHECK_EQUAL(boost::math::hypot(-inf, -boundaries[j]), inf);
}
}
}
BOOST_AUTO_TEST_CASE( test_main )
{
BOOST_MATH_CONTROL_FP;
test_boundaries();
test_spots();
}